Single hand electric alarm clock



May 31, 1&55 v, LEHNER 2,709,331

SINGLE HAND ELECTRIC ALARM CLOCK Filed Dec. 22, 1950 3 SheetsSheet l y31, 1955 v. E. LEHNER 2,709,331

SINGLE HAND ELECTRIC ALARM CLOCK Filed Dec. 22, 1950 3 She e'hs sheet 2v. E. LEHNER 2,709,331.

SINGLE HAND ELECTRIC ALARM CLOCK Filed Dec. 22, l950 3 Sheets-Sheet 3United States Patent SINGLE HAND ELECTRIC ALARM CLOCK Victor ErnestLehner, Gent, Switzerland Application December 22, 1950, Serial No.202,195

1 Claim. (Cl. 58-19) The invention relates to a single hand electricalarm clock comprising a time indicating member which consists of a discwith a graduated section, the angle at the center of which amounts to30", this disc being arranged in the same plane as the time dividingring which is surrounding it. An adjustable hand may also be provided onthis disc to extend over the time dividing ring. At least one ringsection of the time indicating disc is trans parent so that the positionof the alarm clock setting contacts located behind the time indicatingdisc may easily be recognized.

The drawings show the execution of an electric alarm clock according tothe invention.

Fig. l is a longitudinal section through a single band electric alarmclock embodying the invention.

Fig. 2 is a front view of the alarm clock of Fig. 1.

Fig. 3 is a front view, partially in section, of the control switch.

Fig. 4 is a side view of the control switch of Fig. 3.

Fig. 5 is an electric circuit employable for the alarm bell.

Referring to Fig. l, a synchronous motor 1 is used as driving means forthe clock work and is connected to the light net by means of an electriccord 44 and an electric plug 46 (Figs. 3 and 5). The synchronous motor 1is mounted on a flange 3 which is concentrically arranged to the motoraxle 6 and is connected to the latter by means of a rigid coupling. Theflange has an extension inserted into and fastened Within a recessdisposed in the center of vertical plate 4. A bearing 5 also isconcentrically connected to the flange 3. A knob is mounted at the fronton the axle 6 and exerts by means of a spring 21 pressure on the wall ofthe slidable hub 22, the time indicating disc 18 which is fastened tothe hub being pressed against the friction disc 17; the latter one isrigidly connected to the driving axis 6. The rotation of the axle 6 istransmitted to the time indicating disc 18 by means of the friction disc17. Any rotation of the knob 20 to the left or to the right decreases orincreases, respectively, the tension of the spring 21; for the purposeof setting the time indicating disc 18, it is necessary to turn the knob20 that far to the left that the friction between the friction disc 17and the time indicating disc 18 will sufiiciently be reduced to allowthe latter to be turned.

Referring to Fig. 2 which shows a front view of the alarm clock, thecasing 24 comprises a time dividing ring 23 with twenty-four radiallydirected time dividing marks, indicating the hours as well as the halfhours. The transparent time indicating disc 18 comprises a graduatedsection or sector, the angle at the center of which amounts to 30, theleading radially directed edge of the section forming a hand 19 which isnot transparent; the interval between two dividing marks of thegraduated section amounts to five minutes, while single minutes are tobe estimated. The play between the time indicating disc 18 and the inneredge of the time indicating ring 23 amounts to about 2 mm., thuspreventing any friction between disc ice and ring. The double contactmember consisting of the two single alarm bell setting contacts 13 and13a which are insulated from each other, can be recognized through thetransparent time indicating disc 18. Disc 18 carries on the inner sidethereof a contact pin 14 (Fig. 1) which is located behind the hand 19and exactly in line with same; this contact pin 14 on the one hand isconnected to a sliding contact 15 and on the other hand passes over thealarm bell setting contacts 13 and 13a in the moment the hand 19 of thetime indicating disc 18 reaches that position; provided that the controlswitch is in the alarm bell position, this contact pin 14 will close thealarm bell circuit as will be later described. The knob 31 by means of asetting axle 25 as well as by means of the rubber member 26 beingmounted on it, serves to set the alarm bell contact disc 11 as well asthe alarm bell setting contacts 13 and 13a which are provided on it.

Spring 28 seated on setting axle 2S and abutting with one end againstthe vertical plate 4 and with its other end against an abutment sleeve20 which is mounted on the axle 25, is pressed through ball member 30against a ball socket of the end plate 33. The axle 25 is also securedagainst lateral displacement by means of a leaf spring 27, the pressurethereof being exerted on the axle whereby the rubber member 26 ispressed toward the alarm bell contact disc 11.

One or eventually two light bulbs 32 which suitably are elongatedilluminate the time indicating disc 18 as well as the outer side of thealarm clock casing 24. For the purpose of also using the alarm clock asa reading lamp, the pivotally mounted cover 35 comprises on its innerside a mirror 37, which thus provides an indirect illumination. Thelight rays thereby pass from the bulb 32 through the opening 36 in theuppermost part of the alarm clock casing 24.

The switch 38 (Figs. 3, 4) serves as a control member for the alarmclock and comprises four contacts 40, 41, 42 and 43 (Figs. 3 and 5) aswell as a rotating member 39 which alternately connects the contacts4243 and 43, corresponding to the two positions light and alarm bellrespectively. When turned to the light position, the switch 38 closes acircuit which is set up as follows: Phase 1 of the power line 47, switchcontact 43, rotating member 39, switch contact 42, line 52, light pbulbs 32, phase 2 of the power line.

When turned to the alarm bell position, the switch 38 closes a circuitwhich is set up as follows: Phase 1 of the power line 47, switch contact43, rotating member 39, switch contact 40, line 48, sliding contact 9,contact ring 10, sliding contact 12, contact ring 16, sliding contact15, contact pin 14, alarm bell contact 13 or 13a, contact ring 8,sliding contact '7, line 49, transformer 50, phase 2 of the power line.The switch is connected to the alarm clock by means of a flexible threeconductor cord 44, and furthermore is provided with a suction member 45by means of which it can be attached to any desired object, and alsoeasily removed again.

In order to actuate the alarm bell, the described circuit must beadjusted by switch 38, whereupon the contact pin 14 (Fig. 1) which ismounted on the time indicating disc 18 behind the hand 19 and in linewith same, will contact with one of the two alarm bell setting contacts13 or 13a. These two contacts are insulated from each other, providingthus two separated alarm signals which will sound with an interval ofabout five minutes between them; the duration of this interruptionnaturally can easily be varied by suitably choosing the width of theinsulation. Assuming that the switch 38 may now be in the alarm bellposition and the hand 19 of the time indicating disc 13 will pass overthe alarm bell setting contact 13, the alarm bell will ring for about 45seconds, corresponding to the time the contact pin 14 requires to passover this contact 13;

after the sait interruption has taken place, the contact pin 14 thenwill pass over the contact 13a and the alarm bell will ring a second re. The second alarm signal naturally Wiii not oun 1 case he switch 38has in the meantime been to to the light position or even been turnedoff to re t on contacts lt40. It should furthermore be recognized thatthe time indicating device will not be a cted by either of thesediiferent switch positions as the driving motor is directly connected tothe two phases of the power line.

The execution of the invention shows an alarm clock with a timeindicating disc 18, comprising at the center of the graduated section anangle of 30 which corresponds to the angle between two marks, indicatingthe hours on the time dividing ring 23. It is possible in this case toaccurately read the time. This accuracy as a rule meets the requirementsclaimed for alarmand various other clocks. in case of clocks to besuspended from walls it might be advisable to provide the timeindicating ring 23 with a twenty-four hours division, while the angle atthe center of the graduated section of the time indicating disc aanountsto 15. The accuracy of reading the time may also be improved by furthersubdividing the angle of 30 at the center of the graduated section.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent, is:

A single-hand electric alarm clock comprising a time indicating discincluding a sector graduated to correspond with predetermined timeintervals, a time dividing ring surrounding said time indicating discand arranged in the same plane as the latter, one edge of said graduatedsector of said time indicating disc carrying a hand partially projectingover said time dividing ring for convenient visual inspection of timereadings, said time indicating disc including a hub portion rotatabletherewith, a driving axle supporting said hub portion of said timeindicating disc, a manually operable control knob disposed on saiddriving axle on one side of said time indicating disc, a friction discfixedly mounted on said driving axle on the opposite side of saidindicating disc, and spring means interposed between said knob and saidhub portion of said time indicating disc for normally maintainingoperative frictional driving contact between said friction disc and saidtime indicating disc, said knob being adjustable for overcoming theoperative frictional driving contact between said friction disc and saidtime indicating disc for selective adjustment of said time indicatingdsc.

References Cited in the file of this patent UNITED STATES PATENTS

